code: def test_encode_categorical_multiple_column_names(df):
      """
      Test output when more than one column is provided
      to `column_names`.
      """
      result = df.astype({"a": "category", "cities": "category"})
      assert_frame_equal(
          df.encode_categorical(column_names=["a", "cities"]),
          result,
      )
  
imports: import datetime
  import numpy
  import pandas
  import pytest
  from hypothesis import given, settings
  from pandas.testing import assert_frame_equal
  from janitor.testing_utils.strategies import categoricaldf_strategy, df_strategy
label_desc: Use image node_id 5 for calling a global function with example usage: test_encode_categorical_multiple_column_names(df) without return types